InCHIANTI is being performed in two sites: Greve in Chianti (Site 1; 11,709 inhabitants; 19.3% > 65 years; located in the middle of a rural area) and Bagno a Ripoli (Village of Antella, site 2, 4704 inhabitants; 20.3% > 65 years; located immediately adjacent to the urban area of Florence). To obtain two representative samples of the population, the same two stage sampling procedure was used in each of the two sites. For the baseline cohort, in August 1998, a random sample of 1270 persons aged 65 years or older was randomly selected from the population registry of the two sites. Another 29 subjects were randomly selected among those who were 90 years old or older, until at least 30 men and 30 women from this age group were included in the sample. Finally, men and women randomly sampled from the age strata 20-29, 30-39, 40-49, 50-59, and 60-64 years were sequentially invited to participate in the study, until at least 30 men and 30 women for each decade from 20 to 59, and 15 men and 15 women aged 60 to 64 had been enrolled. The InChianti Study cohorts were assessed at baseline in 1998-2000, 3 years later, in 2001-2003, 6 years later, in 2004-2006, and 9 years later, in 2007-2009. As at the three- and six-year follow-ups, the nine-year follow-ups repeated most elements of the baseline evaluation. As at the baseline there were three contacts with participants, once in their homes and on two subsequent occasions in the clinic. Subjects who refused the interview were contacted several more times, one month apart, before being considered definitive refusals. Interviews were conducted at the participants' homes by experienced interviewers. In persons who score 18 or less on the Mini Mental State Examination the interview was administered to a proxy.